This invention relates to a fluid conduit coupling device which allows the simultaneous coupling or uncoupling of pairs of fluid conduits substantially without the loss of process fluid or the introduction of air or ambient fluid, and which will automatically uncouple with the application of a predetermined tensile force.
It is desirable to have a means of coupling and uncoupling fluid conduits such as hoses without the need to drain the hoses prior to coupling or risk fluid loss. Moreover, it is desirable to have a means to couple fluid conduits without introducing contaminants such as ambient fluids and air into the process fluid. In situations where it is foreseeable that it might be necessary to uncouple the fluid conduits very quickly, or under other circumstances preventing the use of a manually actuated release, it is desirable to have a means of disconnecting the fluid conduits by the application of a predefined amount of tensile force on the fluid conduits, preferably without damage to the conduits or the coupling, and in a manner allowing rapid recoupling without the need for prior repair. Such decoupling should occur without fluid leakage from the conduits.
Such quick-connect/quick disconnect dry-break connectors are especially desirable for use with liquid-circulating personal temperature maintenance systems, particularly when such devices are used by those piloting or driving vehicles from which rapid ejection, possibly followed by reconnection, may become necessary.
Numerous detachable fluid conduit coupling systems are known in the prior art. Many such devices employ spring-loaded ball-type valves which may reduce the loss of process fluid upon uncoupling. Such systems are described in U.S. Pat. No. 4,105,046 of Sturgis, and U.S. Pat. No. 5,092,364 of Mullins, both of which describe detachable fluid couplings. However, systems of this type fail to provide a means to substantially prevent the introduction of contaminants such as air and ambient fluids into the process fluid upon coupling. This is because the spring-loaded ball type valves lack a means to expel potentially contaminating materials from the valve surfaces prior to joining.
U.S. Pat. No. 4,794,937 of Hoffman describes a plug and socket-type plug coupling designed for application in high pressure systems. The design of this coupling necessitates the use of gaskets recessed within the coupling apparatus and does not provide a means of expelling ambient fluids or air prior to coupling.
Most fluid coupling systems are not adapted to allow damage-free separation of the connector ends upon the application of tensile force when a manual release mechanism has not been actuated. This can result in the loss of significant quantities of process fluid due to conduit rupturing when emergency separation becomes necessary. In situations where the process fluid is potentially dangerous, this can pose a substantial hazard. Moreover, should separation not occur under conditions where it is necessary the device through which fluid was being circulated may be dragged behind or into the fluid source device, resulting in injury and property damage.
U.S. Pat. No. 5,529,085 of Richards et al teaches a breakaway hose coupling designed to limit the loss of process fluid upon the separation of the coupling. This design relies on the breakage of shear pins to effect release of the coupled hoses. Thus, while an emergency release system is provided, it is not a quick-connect/quick release system. Moreover, design is not adapted to exclude ambient fluid and air upon hose coupling.
The most common commercially available fluid quick-connector types known to the inventors are those produced by Colder Products Company of Minnesota, U.S.A. Features of these connectors are detailed in U.S. Pat. Nos. 4,436,125, 4,541,457, 4,911,655, 5,033,777, 5,052,725, 5,104,158, 5,126,041, 5,494,074, 5,845,943, and D357,307 and D384,712. Some connectors manufactured by Colder Products Company purport to have self-sealing valves. However, due to design factors, a substantial amount of process fluid is typically lost when these valves are uncoupled, and a substantial amount of ambient fluid or air is introduced into the process fluid upon coupling. Moreover, no Colder Products Company valve is known to the inventors which uncouples automatically upon the application of a predetermined tensile force.
It is thus an object of the present invention to provide a fluid conduit coupling apparatus which allows quick connection and disconnection with substantially no introduction of ambient fluids or air into the process fluid.
In one aspect of the invention there is provided a quick connect/disconnect coupling for a fluid conduit, the coupling comprising assemblies for attaching to the ends of a conduit to be connected and for subsequently mating together, each assembly comprising a normally closed channel; means for expelling fluid from between the assemblies when the assemblies are to be connected to each other; means for preventing fluid from entering the assemblies from outside when the assemblies are being connected; means for opening the normally closed channels, means operable by the connecting of the assemblies to each other; latch means for securing the assemblies together, the latch means disconnectable by means of a hand operated unlatching means or by the application of a predetermined tensile force.